H1B - 6th Year - Perm Filed - H4 Dependents status what will happen


I got a question.
I am in my 6th year H1B and is expiring on Feb 2021 and the same is for my dependents.
My Perm was filed on Aug 2020.
I was out of the country for about 2 months and that can be recaptured.
Lets say if my extension for recapture is approved. After which if I apply for my dependents change of status (their extension) and if it is not approved before Feb 2021 what they should do?
Could you please let me know?

Thank you.

Dependent’s status depends on primary status.

Thank you for the response